Extensive theoretical studies of polynitrotriprismanes C6H6-n, (NO2) n (n=1∼6): stability, detonation properties, and pyrolysis mechanisms

To further test whether polynitriprismanes can be capable of being potential high energy density materials (HEDMs), extensive theoretical calculations have been carried out to investigate on a series of polynitrotriprismanes (PNNPs): C6H6-n, (NO2)(n)(n=1 similar to 6). Heats of formation (HOFs), strain energies (SE), and disproportionation energy (DE) are obtained using B3LYP/6-311+G (2df, 2p)//B3LYP /6-31G* method by designing different isodesmic reactions, respectively. Detonation properties of PNNPs are obtained by the well-known Kamlet-Jacobs equations, using the predicted densities (p) obtained by Monte Carlo method and HOFs. It is found that they increase as the number of nitro groups n varies from 1 to 6, and PNNPs with have excellent detonation properties. The relative stability and the pyrolysis mechanism of PNNPs are evaluated by calculated bond dissociation energy (BDE). The comparison of BDE suggests that rupturing the C-C bond is the trigger for thermolysis of PNNPs. The computed BDE for cleavage of C-C bond (21.08kcal.mol(-1)) further demonstrates that only the hexanitrotriprismane can be considered to be the target of HEDMs.